Psykos is a pretty powerful telepath. Her barrier can block almost all kinds of attacks but Cumber would be able to break through with minimal effort. It’s hard to even accurately describe how powerful his attacks are. He’s really just plain unstoppable and that’s what makes him so terrifying. Try as she might, Psykos won’t be able to stop his advances. Even if she fires off her most powerful attack which would end the world with ease, Cumber can end whole star systems. His energy blast would prevail. Cumber wins.